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Evolution of selenoproteins in the metazoan.

Jiang L, Ni J, Liu Q - BMC Genomics (2012)

Bottom Line: Amphioxus was found to have the most abundant and variant selenoproteins of any animal currently characterized, including a special selenoprotein P (SelP) possessing 3 repeated Trx-like domains and Sec residues in the N-terminal and 2 Sec residues in the C-terminal.During evolutionary history, only a few new selenoproteins have emerged and few were lost.Furthermore, the massive loss of selenoproteins in nematodes and insects likely occurred independently in isolated partial evolutionary branches.

View Article: PubMed Central - HTML - PubMed

Affiliation: College of Life Sciences, Shenzhen University, Shenzhen, 518060, Guangdong Province, PR, China.

ABSTRACT

Background: The selenocysteine (Sec) containing proteins, selenoproteins, are an important group of proteins present throughout all 3 kingdoms of life. With the rapid progression of selenoprotein research in the post-genomic era, application of bioinformatics methods to the identification of selenoproteins in newly sequenced species has become increasingly important. Although selenoproteins in human and other vertebrates have been investigated, studies of primitive invertebrate selenoproteomes are rarely reported outside of insects and nematodes.

Result: A more integrated view of selenoprotein evolution was constructed using several representative species from different evolutionary eras. Using a SelGenAmic-based selenoprotein identification method, 178 selenoprotein genes were identified in 6 invertebrates: Amphimedon queenslandica, Trichoplax adhaerens, Nematostella vectensis, Lottia gigantean, Capitella teleta, and Branchiostoma floridae. Amphioxus was found to have the most abundant and variant selenoproteins of any animal currently characterized, including a special selenoprotein P (SelP) possessing 3 repeated Trx-like domains and Sec residues in the N-terminal and 2 Sec residues in the C-terminal. This gene structure suggests the existence of two different strategies for extension of Sec numbers in SelP for the preservation and transportation of selenium. In addition, novel eukaryotic AphC-like selenoproteins were identified in sponges.

Conclusion: Comparison of various animal species suggests that even the most primitive animals possess a selenoproteome range and variety similar to humans. During evolutionary history, only a few new selenoproteins have emerged and few were lost. Furthermore, the massive loss of selenoproteins in nematodes and insects likely occurred independently in isolated partial evolutionary branches.

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AphC.like proteins in sponges.A. The coding regions are indicated by green rectangles, the untranslated regions by blue rectangles, and the SECIS elements by orange rectangles. An intron is indicated by lines connecting the exons. The position of each site in the sequence of the chromosome or scaffold is shown by numbers and bottom coordinates. The position of the Sec-TGA codon is highlighted by the rectangular box around the number. B. The multiple alignment of AphC.like proteins and 4 Sec-containing prokaryotic AphC proteins are shown with Sec residues highlighted with a green background. Species names are listed on the left. C. The SECIS elements of all Aq.AphC.like genes of Amphimedon queenslandica are shown with Cove Scores.
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Figure 1: AphC.like proteins in sponges.A. The coding regions are indicated by green rectangles, the untranslated regions by blue rectangles, and the SECIS elements by orange rectangles. An intron is indicated by lines connecting the exons. The position of each site in the sequence of the chromosome or scaffold is shown by numbers and bottom coordinates. The position of the Sec-TGA codon is highlighted by the rectangular box around the number. B. The multiple alignment of AphC.like proteins and 4 Sec-containing prokaryotic AphC proteins are shown with Sec residues highlighted with a green background. Species names are listed on the left. C. The SECIS elements of all Aq.AphC.like genes of Amphimedon queenslandica are shown with Cove Scores.

Mentions: Three Aq.AphC.like proteins were found in the Amphimedon queenslandica genome. Two of them were tandemly located in one scaffold, and thus named Aq.AphC.like_a and Aq.AphC.like_b. Both coding regions of Aq.AphC.like_a and Aq.AphC.like_b consist of 2 coding exons. Additionally, the amino acid and SECIS elements are homologous. The third member of this family was found in another scaffold, and thus named Aq.AphC.like_c. Aq.AphC.like_c consists of 5 coding exons. Multiple alignments between Aq.AphC.like proteins and prokaryotic AphC are shown in Figure‚ÄČ1.


Evolution of selenoproteins in the metazoan.

Jiang L, Ni J, Liu Q - BMC Genomics (2012)

AphC.like proteins in sponges.A. The coding regions are indicated by green rectangles, the untranslated regions by blue rectangles, and the SECIS elements by orange rectangles. An intron is indicated by lines connecting the exons. The position of each site in the sequence of the chromosome or scaffold is shown by numbers and bottom coordinates. The position of the Sec-TGA codon is highlighted by the rectangular box around the number. B. The multiple alignment of AphC.like proteins and 4 Sec-containing prokaryotic AphC proteins are shown with Sec residues highlighted with a green background. Species names are listed on the left. C. The SECIS elements of all Aq.AphC.like genes of Amphimedon queenslandica are shown with Cove Scores.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3473315&req=5

Figure 1: AphC.like proteins in sponges.A. The coding regions are indicated by green rectangles, the untranslated regions by blue rectangles, and the SECIS elements by orange rectangles. An intron is indicated by lines connecting the exons. The position of each site in the sequence of the chromosome or scaffold is shown by numbers and bottom coordinates. The position of the Sec-TGA codon is highlighted by the rectangular box around the number. B. The multiple alignment of AphC.like proteins and 4 Sec-containing prokaryotic AphC proteins are shown with Sec residues highlighted with a green background. Species names are listed on the left. C. The SECIS elements of all Aq.AphC.like genes of Amphimedon queenslandica are shown with Cove Scores.
Mentions: Three Aq.AphC.like proteins were found in the Amphimedon queenslandica genome. Two of them were tandemly located in one scaffold, and thus named Aq.AphC.like_a and Aq.AphC.like_b. Both coding regions of Aq.AphC.like_a and Aq.AphC.like_b consist of 2 coding exons. Additionally, the amino acid and SECIS elements are homologous. The third member of this family was found in another scaffold, and thus named Aq.AphC.like_c. Aq.AphC.like_c consists of 5 coding exons. Multiple alignments between Aq.AphC.like proteins and prokaryotic AphC are shown in Figure‚ÄČ1.

Bottom Line: Amphioxus was found to have the most abundant and variant selenoproteins of any animal currently characterized, including a special selenoprotein P (SelP) possessing 3 repeated Trx-like domains and Sec residues in the N-terminal and 2 Sec residues in the C-terminal.During evolutionary history, only a few new selenoproteins have emerged and few were lost.Furthermore, the massive loss of selenoproteins in nematodes and insects likely occurred independently in isolated partial evolutionary branches.

View Article: PubMed Central - HTML - PubMed

Affiliation: College of Life Sciences, Shenzhen University, Shenzhen, 518060, Guangdong Province, PR, China.

ABSTRACT

Background: The selenocysteine (Sec) containing proteins, selenoproteins, are an important group of proteins present throughout all 3 kingdoms of life. With the rapid progression of selenoprotein research in the post-genomic era, application of bioinformatics methods to the identification of selenoproteins in newly sequenced species has become increasingly important. Although selenoproteins in human and other vertebrates have been investigated, studies of primitive invertebrate selenoproteomes are rarely reported outside of insects and nematodes.

Result: A more integrated view of selenoprotein evolution was constructed using several representative species from different evolutionary eras. Using a SelGenAmic-based selenoprotein identification method, 178 selenoprotein genes were identified in 6 invertebrates: Amphimedon queenslandica, Trichoplax adhaerens, Nematostella vectensis, Lottia gigantean, Capitella teleta, and Branchiostoma floridae. Amphioxus was found to have the most abundant and variant selenoproteins of any animal currently characterized, including a special selenoprotein P (SelP) possessing 3 repeated Trx-like domains and Sec residues in the N-terminal and 2 Sec residues in the C-terminal. This gene structure suggests the existence of two different strategies for extension of Sec numbers in SelP for the preservation and transportation of selenium. In addition, novel eukaryotic AphC-like selenoproteins were identified in sponges.

Conclusion: Comparison of various animal species suggests that even the most primitive animals possess a selenoproteome range and variety similar to humans. During evolutionary history, only a few new selenoproteins have emerged and few were lost. Furthermore, the massive loss of selenoproteins in nematodes and insects likely occurred independently in isolated partial evolutionary branches.

Show MeSH
Related in: MedlinePlus